Spotless Sun

 There are currently no sunspots visible on the face of the sun.  It is blank.

 This image was taken with a Sightron Infini D50 refractor (50mm, f/10.8) and a front-mounted solar filter.

infini D50

 Compare the spotless image above to the sun two weeks ago on 7 February, when a large active sunspot group was traversing the face:

7 February, AT72EDII refractor.

 Sunspots may be absent, but the sun is far from quiet.  Many large prominences are visible around the rim in hydrogen-alpha light.

Today, 22 Feb. Hydrogen-alpha sun.  Lunt LS50THa double-stacked.

 

false-color image.

The Moon at 4.7 days

 Tonight  (Saturday) the Moon is 4.7 days past new.  This image was taken with an Orion 80mm ED f/7.5 refractor and Olympus E-M5iii camera.  The large circular feature near the middle on the terminator is Mare Nectaris.

 

Some more star clusters and four nearby stars

 The telescope used last night was an Astro-Tech AT72EDII refractor with an Astro-Tech 0.8x focal reducer.  This combination gives a focal length of 346 mm at f/4.8.  This reducer shows very little corner vignetting on the micro-four-thirds sensor of the E-M5iii camera, unlike the Metabones 0.71x Speedbooster. Sky brightness was 19.72 mpsas, which is on the better side of average for this location.  Exposures were either 30 sec or 40 sec at ISO 1600.

 

NGC 2281, an open cluster in Auriga.  2-deg FOV.

 

M44, the "Beehive Cluster", in Cancer.  2-deg FOV.

M67, the "Golden Eye Cluster", in Cancer.  2-deg FOV.

NGC 2232 in Monoceros. 2-deg FOV.

NGC 2244 in Monoceros.  2-deg FOV.

The open cluster NGC 2244 lies at the heart of the Rosette Nebula in the constellation Monoceros.  The nebula is too faint to show up easily in a 40-sec exposure with this optical configuration, but some extreme contrast enhancement reveals its presence:

 There are 37 star systems closer than 15 light years (ly).  Eleven of these systems contain either two or three stars, so there are 50 stars total within this distance.  Only seven of these 50 stars (or pairs) are bright enough to be seen without optical aid.  Most of the nearest stars are red dwarfs (38 out of 50), all of which require a telescope to be detected.  This is the most numerous type of star in the galaxy.

Images were obtained for three of these nearby red-dwarf stars:  Ross 614 in Monoceros, Luyten's Star in Canis Minor, and DX Cancri in the constellation Cancer.

Finder chart for three nearby red dwarf stars.  credit: SkySafariAstronomy.com

 

Ross 614 is a red-dwarf double star that lies just north of the open cluster NGC 2232 in the constellation Monoceros.  Ross 614 is 13.36 ly distant and is the 29th closest star system.  Its two components have magnitudes of 11.2 and 14.2.

Ross 614, top circle.  NGC 2232, bottom circle.

 

Ross 614.  1-deg FOV.

Luyten's Star is a 12.4-magnitude red dwarf that lies about 3 deg from the bright star Procyon in the constellation Canis Minor.  Procyon is a double star that is the 8th brightest star and the 13th closest star system at 11.4 ly .  Luyten's Star is the 22nd closest system at a distance of 12.35 ly.  These two stars are also close companions in space, with a separation of about 1.2 ly.

Procyon (left) and Luyten's Star (circled, right). Rokinon 135mm lens.

 

Luyten's Star.  1-deg FOV.

DX Cancri is the 17th closest star system and shines at magnitude 14.8 (faint!) in the constellation Cancer.

DX Cancri.  1-deg FOV.

 

Two early-evening clusters

Rigel, the brightest star in the constellation Orion, crosses the Meridian near 8 pm.   To the east of Orion lies Jupiter, currently the brightest object in the evening sky.  Farther to the east are two star clusters, M44 and M67, that are better positioned for viewing a couple hours later.  

In the image below, M44 (the "Beehive Cluster") is circled.  M67 lies about 8 deg to the south of M44. Equipment: Olympus E-M1iii + Leica 9mm f/1.7 + Hoya Sparkle-6 filter.

View toward the SSE. 8 pm.

 The sky brightness at 10 pm was sqml=19.73–77, an improvement from recent nights.

M44, the Beehive Cluster.  40 sec, ISO 1600. 2.4-deg-wide FOV.

 This image of M44 (and M67 below) was obtained with the AT72EDII refractor and a Metabones 0.71x Speedbooster, for a final focal length of 307mm at f/4.3.  The camera was an Olympus E-M5iii.

M67. 1-deg FOV.

 M67, also known as the "Golden Eye Cluster", is one of the oldest open clusters in our galaxy.  It is between 4 and 5 billion years old, about the same age as the Sun.  At one time there was speculation that our sun may have originated in this cluster, but that is now thought to be unlikely.

M67, 2-deg FOV.  Rokinon 135mm f/2 + Olympus E-M5.

 

Leica 9mm + Sparkle-6 filter.  9:16 pm 08 Feb.

M44 and M67

Sirius, the Dog Star

 The brightest star in the night sky is Sirius.  As the brightest star in the constellation Canis Major (the Great Dog), it is also known as the Dog Star.

The waning Snow Moon is now rising late enough to provide a period of darkness in the early evening for testing lenses.  The newest lens is a Rokinon AF 75mm f/1.8 FE for Sony E-mount cameras.  The following images were obtained with this lens on a Sony A7iii camera.  Exposures were between 20 and 30 sec at ISO 1600.  The measured sky brightness was sqml=19.58 mpsas.

Sirius and Canis Major.  Hoya Sparkle-6 filter.

 

Hoya Softon-A filter.

Sometimes the diffraction pattern produced by the Sparkle-6 filter is too obtrusive.  In those cases the Softon filter provides a more natural aesthetic.  Unfortunately, the Softon filter does not preserve red star colors as well.  

Orion.  Softon-A filter.

Messier 41 (M41) is a nice open star cluster that lies about 4 deg south of Sirius.  These two image crops help to demonstrate the relative color response of the two filters. Note especially the trio of reddish stars to the right between Sirius and M41.

Hoya Sparkle-6 filter.

Hoya Softon-A filter.

Three Rokinon lenses.  The new 75mm lens is on the right.

Rokinon is the brand label used for Samyang lenses in the North American market, although the same lens is frequently available with either label from the same vendor.

Active Sun: 3 Feb

 There is a large sunspot group generating strong flares that may produce geomagnetic storms.  There are also many large prominences visible along the limb of the sun (in Hydrogen-alpha light).

White light.  Orion 80mmED + front filter.

 

Hydrogen-Alpha light.  Lunt LS50THa double-stacked.

false-color Hydrogen-Alpha.

The Sun and the Snow Moon

 The full moon of February is traditionally known as the "Snow Moon".  This year it occurred on Sunday, 1 February.  

Snow Moon rising

Snow Moon.  Orion 80mmED refractor.

There is a large active sunspot group rotating into view on the Sun:

Orion 80mmED with front-mounted solar filter.

 

2x enlargement